Hall plot analysis,as a widespread injection evaluation method,however,often fails to achieve the desired result because of the inconspicuous change of the curve shape.Based on the cumulative injection volume,injectio...Hall plot analysis,as a widespread injection evaluation method,however,often fails to achieve the desired result because of the inconspicuous change of the curve shape.Based on the cumulative injection volume,injection rate,and the injection pressure,this paper establishes a new method using the ratio of the pressure to the injection rate（RPI） and the rate of change of the RPI to evaluate the injection efficiency of chemical flooding.The relationship between the RPI and the apparent resistance factor（apparent residual resistance factor） is obtained,similarly to the relationship between the rate of change of the RPI and the resistance factor.In order to estimate a thief zone in a reservoir,the influence of chemical crossflow on the rate of change of the RPI is analyzed.The new method has been applied successfully in the western part of the Gudong 7th reservoir.Compared with the Hall plot analysis,it is more accurate in real-time injection data interpretation and crossflow estimation.Specially,the rate of change of the RPI could be particularly suitably applied for new wells or converted wells lacking early water flooding history.展开更多
This paper attempts to explore the temporal and spatial nature of the marginal revenue of land, total factor productivity （TFP） change and its three components： technical change （TC）, technical efficiency change ...This paper attempts to explore the temporal and spatial nature of the marginal revenue of land, total factor productivity （TFP） change and its three components： technical change （TC）, technical efficiency change （TEC） and scale efficiency change （SEC） as seen in Chinese agricultural production from 1995 to 1999. Based on county-level data, the study utilized both stochastic frontier and mapping analyses methods. The results show that growth in the marginal revenue of land was diverse across various regions, where most gain occurred in eastern coastal zone, while loss was in Northwest and North China. China has experienced moderate decreases in annual TFP change （–0.26%） with considerable regional variations. Specifically, the administrative intervention in grain production and the deterioration of the agricultural technology diffusion system led to a moderate drop in annual TFP change. County-level mapping analyses took into account interregional variances in TFP and its components. Regarding components of TFP, TEC differences explain the majority of regional dispersions in TFP. As developed areas in China, the Huang-Huai-Hai region and the Beijing-Tianjin-Tangshan economic zone face the challenges of land conversion and grain security amidst the process of urbanization.展开更多
CRISPR-Cas system has been widely adapted as a platform for genome editing in various eukaryotic organisms, including zebrafish（Cong et al., 2013; Hwang et al., 2013）. One of the important applications of CRISPR-Cas...CRISPR-Cas system has been widely adapted as a platform for genome editing in various eukaryotic organisms, including zebrafish（Cong et al., 2013; Hwang et al., 2013）. One of the important applications of CRISPR-Cas9 system is to produce double-strand DNA breaks（DSBs） at targeted sites with guide RNA（gRNA）.展开更多
基金the financial support from the National Natural Science Foundation of China (Grant No. 51574269)the Important National Science and Technology Specific Projects of China (Grant No. 2016ZX05011-003)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No. 15CX08004A, 13CX05007A)the Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT1294)
文摘Hall plot analysis,as a widespread injection evaluation method,however,often fails to achieve the desired result because of the inconspicuous change of the curve shape.Based on the cumulative injection volume,injection rate,and the injection pressure,this paper establishes a new method using the ratio of the pressure to the injection rate（RPI） and the rate of change of the RPI to evaluate the injection efficiency of chemical flooding.The relationship between the RPI and the apparent resistance factor（apparent residual resistance factor） is obtained,similarly to the relationship between the rate of change of the RPI and the resistance factor.In order to estimate a thief zone in a reservoir,the influence of chemical crossflow on the rate of change of the RPI is analyzed.The new method has been applied successfully in the western part of the Gudong 7th reservoir.Compared with the Hall plot analysis,it is more accurate in real-time injection data interpretation and crossflow estimation.Specially,the rate of change of the RPI could be particularly suitably applied for new wells or converted wells lacking early water flooding history.
基金National Basic Research Program of China （973 Program）,No.2010CB950904 National Key Technology R＆D Program of China,No.2008BAK50B06+2 种基金 No.2008BAC43B01 National Natural Science Foundation of China,No.40801231 No.41071343
文摘This paper attempts to explore the temporal and spatial nature of the marginal revenue of land, total factor productivity （TFP） change and its three components： technical change （TC）, technical efficiency change （TEC） and scale efficiency change （SEC） as seen in Chinese agricultural production from 1995 to 1999. Based on county-level data, the study utilized both stochastic frontier and mapping analyses methods. The results show that growth in the marginal revenue of land was diverse across various regions, where most gain occurred in eastern coastal zone, while loss was in Northwest and North China. China has experienced moderate decreases in annual TFP change （–0.26%） with considerable regional variations. Specifically, the administrative intervention in grain production and the deterioration of the agricultural technology diffusion system led to a moderate drop in annual TFP change. County-level mapping analyses took into account interregional variances in TFP and its components. Regarding components of TFP, TEC differences explain the majority of regional dispersions in TFP. As developed areas in China, the Huang-Huai-Hai region and the Beijing-Tianjin-Tangshan economic zone face the challenges of land conversion and grain security amidst the process of urbanization.
基金supported by the funding from the Science and Technology Program of Shenzhen (JCYJ20150924110425180 and JCYJ20151030170755264)
文摘CRISPR-Cas system has been widely adapted as a platform for genome editing in various eukaryotic organisms, including zebrafish（Cong et al., 2013; Hwang et al., 2013）. One of the important applications of CRISPR-Cas9 system is to produce double-strand DNA breaks（DSBs） at targeted sites with guide RNA（gRNA）.
